Field of the Invention
The invention concerns a device for controlling the rotation of door mirrors in motor vehicles.
It is known that the current safety regulations prescribe the collapsibility, under the action of a predetermined force, of the mobile portion of door mirrors, namely the outer cover as well as all the components contained therein and supported therewith by the mirror frame, in respect to a fixed base integral to the vehicle. However the resistance to turnover of the mobile portion of the door mirror must be such as to guarantee at least the maintenance of the outer cover position during the vehicle ride.
There is at the same time the need of allowing a controlled, not casual rotation of the mobile portion up to a predetermined reference position by means of an electric motor.
The solutions proposed in the known technique involve considerable manufacturing difficulties since it is necessary to take into consideration different requirements as regards the cover resistance to shift.
The previous European Patent Application N. 92119911.3 filed by the Applicant proposed a device to perform the controlled rotation of the door mirror by means of an electric motor, wherein the movement of the mobile portion of the door mirror, namely the casing and the outer cover integral thereto, is controlled by a microswitch that allows to detect the only operative position of the door mirror.
Said microswitch enables the electric motor actuation only when the mobile portion of door mirror is in one of preset positions, typically an operative position (or ride position) and a rest position (or parking position) due to a rotation caused by the electric motor. On the contrary, if the rotation takes place because of an external force applied to the movable portion, it is necessary to manually reposition said movable portion in the only operative position. This is due to the presence of a ring provided between the cover and the fixed base, said ring being coupled to the outer cover by means of friction elements and to the fixed base by means of retaining and positioning elastic means of known type (see the Italian Utility Model N. 219560 filed by the Applicant). During the manual rotation of the cover the retaining and positioning elements disengage, while said ring remains coupled with the cover, thanks to said friction elements. The disengagement of the retaining and positioning means involves the changeover of the microswitch and the consequent disablement of the electric motor. On the contrary, in case of motorized rotation, the friction elements, appropriately calibrated, allow the rotation of the outer cover in respect to the ring integral to the fixed base, that is without causing the disengagement of the retaining means and the consequent disablement of the electric motor by the microswitch.
This kind of configuration, though having proved to be functionally effective, involves the use of a very powerful and therefore cumbersome motor as well as the use of friction elements of considerable size.